Scientists at the National Institutes of Health took MRI brain images of people with Havana syndrome, or what the U.S. government calls anomalous health incidents (AHIs). In a 2024 article in JAMA, MRI scans of 81 people who experienced Havana syndrome were compared to 48 people who served as controls. Several months later, 49 of the people with Havana syndrome repeated their MRI. The researchers didn’t find much difference in brain imagery between the people with Havana syndrome and the control condition.
One of the study’s authors, Carlo Pierpaoli, M.D., Ph.D., said these brain imaging results show that Havana syndrome shouldn’t cause concern about permanent changes in the brain. “It is possible that individuals with an AHI may be experiencing the results of an event that led to their symptoms, but the injury did not produce the long-term neuroimaging changes that are typically observed after severe trauma or stroke,” Pierpaoli said in an NIH news release.
Another 2024 NIH study in JAMA conducted balance, hearing, vision, blood biomarkers, and neuropsychological testing on 86 people with Havana syndrome. Compared to controls, people with Havana syndrome reported more fatigue, depression, post-traumatic stress, and neurobehavioral symptoms. However, there were no differences between groups on the objective tests such as balance, vision, and blood biomarkers.